Difference Self-Drilling Self-Tapping Screws

Self-Drilling vs. Self-Tapping Screws

Self-Drilling vs. Self-Tapping Screws. Aren’t they the same screw?  So many different names for the same fastener exist that I wish I had a fastener thesaurus on my desk.  The other day a builder called looking for an expansion bolt. I knew it had another name, but I just couldn’t grasp it. I asked my colleague and he said, “Oh yeah…it is an expansion anchor, or more commonly put… a wedge anchor.” Here I am going to point out some other fasteners synonyms. Then I am going to expand on a couple fasteners that really trip people up; self-drilling vs. self-tapping screws.

Almost every fastener has more than one name. Tapcons are also known as concrete screws. Drop-in anchors also get called female anchors. And sheet metal screws often go by self-tapping screws. There are also instances of the Kleenex, Band-Aid, and Hoover syndrome, where a fastener winds up being called by its originator’s trademark name. Many construction people call a headed anchor stud a Nelson stud. Engineers frequently call socket head fasteners an Allen Head. And builders often call sleeve anchors Red Heads. At Lightning Bolt, if you call out any of the above synonyms, we usually know about what you are needing.  But just realize, it is important to know that fasteners go by many different names that can easily get confused for another. Take a moment to look up your fasteners on the internet to be sure you are ordering the right thing.

Here I am going to point out some other fastener synonyms and I am going to expand on a couple fasteners that really trip people up;  self-drilling vs. self-tapping screws.

Now I will bring up two of the most commonly mixed up items:  self-drilling screws and self-tapping screws. Self-drilling screws have a drill-looking tip for making their own pilot hole. They are often called Tek Screws after the company who invented them and sometimes you will see them abbreviated as SDS.  Generally, self-drilling screws just drill the hole, but there are some that also tap in the threads as well. Self-tapping screws have very sharp threads that cut their threads into the material they are being inserted. These have a very sharp point, especially in contrast with a self-drilling screw. Self-tapping screws are often called sheet metal screws or zip screws and abbreviated SMS. The most important thing to remember is that there is a big difference between self-drilling and self-tapping screws. They are not the same!



See also “Use the Right Fastener for the Right Job”

See also “Get Your Order Right the First Time:  Arm Yourself with some Fastener Knowledge”